RESPIRATION OF FISHES WITH SPECIAL EMPHASIS ON STANDARD OXYGEN CONSUMPTION: II. INFLUENCE OF WEIGHT AND TEMPERATURE ON RESPIRATION OF SEVERAL SPECIES

Abstract

Standard oxygen consumption, as estimated by simultaneously measuring spontaneous activity and oxygen consumption, for five species of freshwater fishes, was measured in relation to weight and temperature. The fish studied were brown trout, Sulmo trutta; brook trout, Salvelinus fontinalis; common white sucker, Catostomus commersonii; brown bullhead, Ictalurus nebulosus; and carp, Cyprinus carpio. When expressed on a logarithmic grid, standard oxygen uptake increased linearly with weight for all species. The proportionate change in standard oxygen consumption for a given change in temperature appears to be independent of size within each species. The mean slope values of the regressions found for brown trout, brook trout, common white sucker, brown bullhead, and carp are 0.877, 1.052, 0.864, 0.925, and 0.894, respectively.The standard rates of oxygen consumption found in the present investigation are less in most cases than the lowest applicable values that could be found in the literature.Spontaneous activity, expressed in terms of average oxygen consumption over the standard rate, varied with temperature. Maximum spontaneous activity for a given species coincided roughly with its preferendum temperature.